Quantum chemical calculations, x-ray structural analysis and thermodyn
amic stability considerations are presented for the dimer phase of AC(
60). The relative stability of dimer and polymer phases was evaluated
from thermodynamic data and critically compared to the results of quan
tum chemical calculations. The AM1 optimized geometry results in a hig
h quality of Rietveld but the spatial distribution of excess charge of
the dimer anion has no significant effect on the structural refinemen
t. (C) 1997 Elsevier Science Ltd.